Air cooling apparatus



A. B. HUBBARD AIR COOLING APPARATUS Filed July 11, 1940 2 Sheets-Sheet lInventor 'Alber't' B. Hubbard 9 His .jll a 7 III 6. AMA ttorneg.

Jan. 6, 1942. A. B. HUBBARD AIR COOLING APPARATUS Filed July 11, 1940 2Sheets- Sheet 2 Invent 01": Albert B. Hubbard Hi S Attorney.

Patented Jan. 6, 1942 UNITED STATES PATENT OFFICE AIR, COOLING APPARATUSNew York Application July 11,1940, Serial No. 344,933 1 Claim.(01.62-140) rangement must alsobe provided for removing wateraccumulated as a result of the condensation of moisture on the coolingcoils; it has become a general practice to provide an arrangement forcollecting the water and for spraying it or otherwise introducing itinto the path of the air circulated over the condenser, therebyvaporizing the water and also providing increased capacity for coolingthe condenser.

It is an object of my invention to provide an air cooling apparatusincluding a refrigerating machine and an improved arrangement forcooling the condenser thereof.-

Another object of my invention is to provide an air cooling apparatusincluding a refrigerating machine having an evaporator and an air cooledcondenser and an improved arrangement for disposing of moisturecondensed on the evaporator.

Another object of my invention is to provide air cooling apparatus ofthe unit type which shall be efficient in operation and of simple andcompact construction.

Further objects and advantages of my invention will become apparent asthe following description proceeds;and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaim annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to theaccompanying drawings in which Fig. 1 is a perspective view partly insection of a room cooling unit embodying my invention; Fig. 2 is asectional side elevation of the unit shown in Fig. l; and Fig. 3 is aperspec- 45 tive view of a portion of the unit shown in Fig. 1 showingthe arrangement of the condenser.

The air conditioning unit illustrated in the drawings comprisesgenerally a casing arranged to be mounted within a window opening and 50havinga partition constituting a continuation of the window closure anddividingthe casing into two portions, one containing the compressor andan air cooled condenser, and the other the evaporator and a fan forcirculating air from the room over the evaporator and back into the vopening at the side may be closed by suitable room. Water collected onthe surface of the evaporator is conducted to a pan at the bottom of thecondenser so that the lowermost coils of the condenser are maintainedimmersed in water. The pan is so arranged that in the event of an excesssupply of water, the overflow will enter. a pan over which the condenserair is circulated and in the event that there is an overflow from thesecond pan, the water will be directed away from the unit out of thewindow opening. The condenser is so arranged that the lowermost coilswhich are immersed in water constitute a hot gas desuperheater orprecooling portion, the condensing portion of the coils being arrangedabove the desuperheating portion, the precooled gas entering the top ofthe condensing portion and flowing downwardly therefrom. Thisarrangement provides a very eflicient use of the cooling capacity of thecondensed water, and particularly is effective in vaporizing the waterand removing it from the unit since the hottest compressed refrigerantvapors are in heatexchange with the water.

Referring now to the drawings, in Fig.1 I have illustrated an airconditioning unit comprising a housing or casing III arranged within awindow opening, the. casing including guide rails ll resting on thewindow sill l2 and providing a support for an airconditioning unit whichmay be slid in and out of the casing on the rails II. The window islowered against the top of the casing I0 and a 'suitable gasket l3 maybe provided between the window sash l4 and a flange l5 at the forwardend of the housing It. The air conditioning unit is arranged to beinserted from the room side of the housing III and a finished cabinet [6having an air outlet ll at its top is arrangedto be placed on the uniton the room side against the flange l5 of the casing l0. Any spacebetween the casing Ill and the window panels 18.

The air conditioning unit comprises a housing l9 arranged to fit withinthe casing I0 and having a vertical longitudinal partition 20 dividingthe housing I9 into two compartments, the partition 20 constituting ineffect a continuation of the window closure; suitable gaskets such asindicated at 2| ar provided to prevent the passage of air through thewindow opening between the casings l0 and I9.

In the compartment formed by the partition 20 in the portion of thecasing I9 on the outer side of the window are arranged a compressor 22driven by a motor 23' and a condenser 24 cooled by an air circulatingfan25 also driven by the motor 23, the fan 25 being directlyconnected tothe motor shaft and the compressor 22 being driven through a belt 26.The condenser 24 comprises a coil having a plurality of horizontal tubesor runs connected by end turns 21 and provided with a plurality of heattrans fer fins 28. A rectangular casing 29 is provided on the right handside of the condenser 24, as viewed in Fig. 1, and has a circularopening 30 for the fan 25. The fan is arranged to force air into thecompressor compartment through the opening 30, the condenser air beingdrawn into the compartment through the right half of the condenser andbeing circulated over the compressor and motor before being dischargedthrough th left half of the condenser. The casing I has its top portionbent downwardly as indicated at 3| to provide a rain shield.

In the compartment formed on the room side of the casing l9 are arrangedan evaporator 32 and a room air circulating fan 33. The evaporator 32comprises a plurality of tubes or runs connected by end turns 34, theruns being provided with a plurality of parallel heat transfer fins 35.The fan 33 is connected on a shaft 35 driven by the motor 23 and belt 26through a pulley 31 as shown in Fig. 2. The fan 33 is arranged to drawair from the room through an opening 38 between the casing l and thecasing l9 and to circulate the air upwardly into the is provided with apartition or dividing wall 56 which in effect provides two pans, one asmall pan directly at the bottom of the condenser 54, and the other apan extending below the motorcompressor unit. Water flowing through theconis of equal height on the endsof the pan and along the side adjacentthe wall 28 of the housing. The portion of the side-wall remote from thepartition is of "a height intermediate that of the main portion and thedividing wall56, as

indicated at 58. This arrangement of the partition 56 and side wall ofthe pan 54 is such that rear portion of the evaporator compartment, the

air being forced through the evaporatortoward the front of thecompartment and out through the opening I 1 which is provided with aplurality of longitudinal louvers 39. The path of the evaporator air isindicated by the arrows in Fig. 2.

During the operation of the refrigerating machine, gaseous refrigerantis withdrawn from the evaporator 32 through a suction line 40 byoperation of the compressor 22. The refrigerant is compressed anddischarged from the compressor through a line 4| and flows into thelowermost runs 42 and 43 of the condenser which are connected in seriesand constitute a hot gas desuperheater or precooler. The gaseousrefrigerant precooled in the tubes 42 and 43 flows through a connection44 to the top tube 45 of the condenser and then downwardly in seriesthrough the remaining tubes until it reaches the bottom one of theremaining tubes indicated at 46. The gas in the condenser is cooled bythe circulating air and liquefied, and the liquid refrigerant flowsthrough a connection 41 to a liquid receiver 48. The liquid refrigerantis returned to the evaporator through a liquid line 49 under control ofa thermostatic expansion valve 58, the valve 50 having a thermal element5| secured in heat exchange relation with the suction line or outlet 40of the evaporator in accordance with common practice.

During the operation of the refrigerating machine, air is circulatedover the evaporator by the fan 33 and is cooled and dehumidified beforebeing discharged through the opening H. The

moisture removed from the air collects in a pan 52 below the evaporatorand flows through a trough or conduit 53 downwardly toward the condenserand falls into a pan 54 which comprises the lower wall of the outercompartment of the casing i9 and is below the condenser andmotorcompressor unit. The motor-compressor unit is supported within thepan 54 by suitable upright brackets 55 at either end thereof. The pan 54any overflow of water from the portion of the pan directly below thecondenser flows into the main portion of the mm below themotor-oompressor unit in the path of the air circulated by the fan 25and any overflow is readily vaporized .by the circulating air. Underconditions of abnormal humidity should the pan 54 be filled above thelevel of the dividing wall 56, the excess water will flow away from theunit over the outer portion 58 of the wall 51. This arrangement affordscomplete vaporization of the water condensed on the evaporator coilunder all normal conditions of operation and a flow of excess waterunder abnormal conditions away from the unit beyond the window sill,indicated at 59. Under no conditions of operation is there an overflowof water toward the room side of the unit. The relative heights of thedividing wall 56 and the walls of the pan 54 may be selected so that theunit may be considerably oil level without danger of flooding back ofthe water toward the room and still provide the advantageous feature ofan arrangement for vaporizing all the water during normal weatherconditions.

In order to insure a minimum transmission of vibration from themotor-compressor unit to the housing l9, the motor and compressor aremounted on a platform 60 which is suspended from the tops of thebrackets 55 on suitable springs 6| and rods 52. The suction line 40 andthe connection 4| which connect the compressor to the condenser andevaporator respectively, are made sufliciently resilient to insureminimum transmission of vibration.

During the operation of the air conditioning unit described above, themotor 23 is started and stopped by any suitable control such as athermostatic control responsive to the temperature of the air within theroom. As long as there is a demand for cooling in the room the motor isoperated to supply liquid refrigerant to the evaporator androom air iscirculated over the surface of the evaporator by the fan 33. Anymoisture condensed on the surface of the evaporator collects in the pan52 and flows to the portion of the pan 54 immediately below thecondenser. The lowermost portion of the condenser is thereby at leastpartly immersed in water and the coils 42 and 43 which receive hotcompressed refrigerant from the compressor constitute a precooler forremoving superheat from the compressed gas. The heat of the hot gasvaporizes the water in the pan. Thewater vapor is removed with the aircirculated over the condenser by operation of the fan 25 and dischargedOutside. The precooled gas enters the top of the condenser and flowsdownwardly through the main condensing portionthereof where further heatis removed from the gas which is thereby liquefied. The circulation ofthe air through the outer compartment of the conditioner also cools themotor and the compressor. Since only precooled or desuperheated vapor issupplied to the main air cooled portion of the condenser, there resultsa considerable reduction in the required surface of the condenser.

From the foregoing, it is readily apparent that I have provided a simpleand effective arrangement of a refrigerating-machine in an air coolingapparatus so that a relatively small space is revquired and so thatmoisture may be removed readily and efllciently from the apparatuswithout danger of the overflow of water toward the room.

While I have described myinvention in connection with an airconditioning unit to be mounted within a window opening,other'applications will readily be apparent to .those skilled in theart. I do not, therefore, desire my invention to be limited to theparticular construction shown and described, and I intend in theappended claim to cover all modifications within the spirit and scope ofmy invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

An air cooling apparatus including a casing having arranged therein arefrigerating machine comprising a compressor and a condenser and anevaporator, a partition in said casing providing two compartments onecontaining said evaporator and the other containing said compressor andsaid condenser, means for circulating air over said evaporator. forcooling and dehumidifying said air, means for circulating air throughsaid other compartment over said compressor and condenser, said casingincluding a pan forming the bottom wall of said second compartment, thelower end of said condenser being arranged within said pan, a dividingwall in said pan having a height less than the height of the wall ofsaid pan for providing .a water reservoir about the lower end of saidcondenser, means. for collecting water condensed on the surface of saidevaporator and for conducting the water to said reservoir, said dividingwall aflording an-overflow of water from said reservoir into the mainportion of said pan, and said pan having a portion of its side wallremote from said partition-of a height less than the remaining portionthereof whereby any overflow of water from said pan is discharged awayfrom said apparatus.

ALBERT B. HUBBARD.

